09 Apr 2009

New publication:

Hierarchical Dirichlet Trees for Information Retrieval. G.R. Haffari, Y. W. Teh . In Proceedings of North American Chapter of the Association for Computational Linguistics - Human Language Technologies (NAACL-HLT), 2009.


We propose a principled probabilistic framework which uses trees over the vocabulary to capture similarities among terms in an information retrieval setting.  This allows the retrieval of documents based not just on occurrences of specific query terms, but also on similarities between terms (an effect similar to query expansion). Additionally our principled generative model exhibits an effect similar to inverse document frequency. We give encouraging experimental evidence of the superiority of the hierarchical Dirichlet tree compared to standard baselines.